Solid catalyst component and catalyst for polymerization of olefins

ABSTRACT

The present invention provides a solid catalyst component (A) obtained by allowing a dialkoxymagnesium or diaryloxymagnesium, a titanium compound, a diester of phthalic acid and a cyclic or chain polysiloxane to come in contact with one another. 
     Further, the present invention provides a catalyst for polymerization of olefins prepared from the foregoing solid catalyst component (A), an organic aluminum compound and an organic silicon compound.

TECHNICAL FIELD

The present invention relates to a solid catalyst component and catalystfor polymerization of olefins which can provide a polymer having a highstereoregularity, excellent particle properties, in particular a highbulk density, and a small content of fine powder in a high yield.

More particularly, the present invention relates to a solid catalystcomponent and catalyst for polymerization of olefins which can provide acopolymer having excellent particle properties in a high yield even ifthe production ratio of rubber-like polymer is raised in the blockcopolymerization of olefins.

TECHNICAL BACKGROUND

Many proposals have been made and known for a solid catalyst componentcomprising a titanium halide compound, a magnesium compound and anelectron donor compound as essential components and a process for thepolymerization of olefins in the presence of a catalyst comprising saidsolid catalyst component, an organic aluminum compound and a thirdcomponent such as a silicon compound.

Further, a solid catalyst component prepared from a dialkoxymagnesiumand titanium tetrachloride as main starting materials and a catalyst forpolymerization of olefins made of said solid catalyst component, anorganic aluminum compound and a third component such as a siliconcompound have been known as disclosed in JP-A-63-3010 (The term "JP-A"as used herein means an "unexamined published Japanese patentapplication"), JP-A-1-221405, JP-A-1-315406, JP-A-3-227309,JP-A-3-70711, JP-A-4-8709, and many other references.

The foregoing various techniques focus on the development of a catalystcomponent which is active enough to allow the omission of a so-calleddeashing step, i.e., step of removing catalyst residues such as chlorineand titanium remaining in the polymer produced by the polymerization ofpropylene in the presence of a catalyst as well as on the enhancement ofthe yield of stereoregular polymer. These techniques can provideexcellent results on these purposes.

However, if a polymerization catalyst having a composition comprisingthis kind of a high activity type catalyst component, an organicaluminum compound and an electron donor compound such as siliconcompound is employed to polymerize olefins, the polymer thus producedcontains much fine powder derived from fine solid catalyst componentitself or obtained by fragmentation due to reaction heat duringpolymerization. Thus, the polymer has a broad particle sizedistribution. As a result, the bulk density of the polymer thus producedtends to drop. If the content of the fine polymer is raised, thecontinuance of uniform reaction can be inhibited. Further, the pipe inthe polymerization process can be blocked. Moreover, some troubles canoccur at the separation step and the drying step of the polymer thusproduced. It has been desired to solve these problems. In addition, ifthe particle size distribution is widened, it eventually givesundesirable effects on the formation of the polymer. If the bulk densityof the polymer thus produced is lowered, the resulting productivity isextremely lowered. This is the reason why a polymer having as small finepolymer content as possible and a high bulk density has been desired.

In order to solve these problems, many methods have been proposed andare known for polymerizing olefins in the presence of a solid catalystcomponent comprising as essential components a magnesium compound suchas dihalogenated magnesium and alkylmagnesium compounds, a titaniumcompound, an electron donor compound and a polysiloxane or a catalystcomprising said solid catalyst component, an organic aluminum compoundand a third component such as a silicon compound. For example,JP-A-61-204202 discloses a catalyst component for polymerization ofolefins prepared by allowing the reaction product of dihalogenatedmagnesium, titanium tetraalkoxide and hydrogenated polysiloxane, an acidhalide compound and a silicon halide compound to come in contact withone another. Further, JP-A56-152811 discloses a process for theproduction of a polyolefin which comprises the polymerization of olefinsin the presence of a catalyst comprising in combination atitanium-containing solid catalyst component derived from analkylmagnesium compound, a polysiloxane, an organic acid ester and atitanium compound and an organic metal compound.

On the other hand, JP-A-6-157659 proposes a catalyst for polymerizationof olefins made of a solid catalyst component obtained by a processwhich comprises adding a suspension of a spherical particulatedialkoxymagnesium, an aromatic hydrocarbon and a diester of phthalicacid to a mixed solution of an aromatic hydrocarbon and titaniumtetrachloride so that they are reacted, and then reacting the reactionproduct with titanium tetrachloride.

Further, JP-A-6-287225 proposes a solid catalyst component forpolymerization of olefins obtained by a process which comprises adding asuspension of a spherical particulate dialkoxymagnesium, an aromatichydrocarbon and a diester of phthalic acid to a mixed solution of anaromatic hydrocarbon and titanium tetrachloride so that they arereacted, washing the reaction product with an aromatic hydrocarbon, andthen again reacting the reaction product with titanium tetrachloride toobtain a solid component which is then dried and freed of fine powder.

Further, JP-A-6-287217 proposes a solid catalyst component forpolymerization of olefins obtained by a process which comprises adding asuspension of a spherical particulate dialkoxymagnesium, an aromatichydrocarbon and a diester of phthalic acid to a mixed solution of anaromatic hydrocarbon and titanium tetrachloride-so that they arereacted, washing the reaction product with an aromatic hydrocarbon,again reacting the reaction product with titanium tetrachloride, dryingthe solid component thus obtained, removing fine powder from the solidcomponent, and then adding a powdered nonionic surface active agent tothe solid component.

The foregoing technique can remove the fine powder derived from thesolid catalyst component itself, eventually exerting an effect ofreducing the content of fine powder in the polymer thus produced.However, the effect of the foregoing technique does not go so far as tocontrol the generation of fine powder due to fragmentation of particlesby the reaction heat during polymerization, in particular in the initialstage of the polymerization reaction. Thus, a fine powder is stillpresent in the polymer thus produced.

Further, the polymer produced according to the foregoing technique has agood morphology but has a low bulk density. In the production of apolyolefin, the amount of a polymer to be produced per unit volume inthe polymerization tank is reduced, and the amount of the polymer to beprocessed during transportation or pelletizing step is limited. As aresult, such a problem that the productivity throughout the entireprocess for the production of polyolefin is reduced is left unsolved.Further, even if a polymer having a relatively high bulk density can beobtained, the problem of drop of polymerization activity orstereoregularity is left unsolved.

From the standpoint of energy saving or conservation of resourcesrelated to the recent global environmental issue, it has been keenlydesired to reduce the weight of plastics for use in automobile,household appliance, etc. In order to solve this problem, the thicknessof molded plastic articles needs to be reduced while maintaining itsstrength such as impact strength. To this end, it is desired to furtherenhance the stereoregularity or crystallinity and hence the rigidity ofthe resin to be used. Accordingly, it has been desired to develop acatalyst for the production of a polyolefin which can provide a polymerhaving an enhanced stereoregularity or crystallinity.

On the other hand, a process for the production of a block copolymer ofpropylene has been known which comprises producing a crystalline polymerof propylene alone in the presence of a solid catalyst component orcatalyst of the various conventional types at a first stage, and thencopolymerizing propylene with another olefin such as ethylene and1-butene in the copresence of said propylene homopolymer at a secondstage.

Such a block copolymer contains a rubber-like copolymer in a certainproportion and thus exhibits an enhanced impact strength whilemaintaining an excellent rigidity characteristic of crystallinepolypropylene. Therefore, such a block copolymer has found wideapplication, e.g., to container, automobile parts such as bumper andfilm requiring low temperature heat sealability.

In order to further enhance the impact strength of such a blockcopolymer, the proportion of a rubber-like copolymer (e.g.,ethylene-propylene rubber) to be produced in the block copolymer needsto be raised. However, as the production ratio of rubber-like copolymerincreases, the adhesion of the particulate block copolymer thus producedincreases. As a result, the flowability of the particulate polymer thusproduced shows a remarkable deterioration in the gas phasepolymerization process or bulk polymerization process. Further, thepolymer particles stick to each other to agglomerate or stick to theinner wall of the polymerization apparatus, causing serious troubles inthe process operation.

For the purpose of eliminating the deterioration of the flowability ofthe particulate block copolymer or the adhesion of the particles causingagglomeration or the adhesion of the particles to the inner wall of theapparatus, JP-A-61-69821 and JP-A-61-69822 propose the supply of anactive hydrogen compound such as ethanol or an oxygen-containingcompound such as oxygen gas into the polymerization system at the secondstage, i.e., stage of producing a rubber-like copolymer. However, suchan active hydrogen compound or oxygen-containing compound originallycauses deterioration of the activity of the catalyst in thepolymerization of olefins. In this process, the amount of such an activehydrogen compound or oxygen-containing compound to be supplied needs tobe closely controlled. Further, the apparatus to be used for thisprocess needs to be improved.

The present invention is intended to solve the foregoing problems of theprior art techniques. In other words, an object of the present inventionis to provide a solid catalyst component and catalyst for polymerizationof olefins which can provide a polymer having a high bulk density and asmall content of fine powder while maintaining the desired highpolymerization activity and high yield of a high stereoregularitypolymer. Another object of the present invention is to provide a solidcatalyst component and catalyst for polymerization of olefins which canmaintain its good particle properties even if the production ratio ofrubber-like copolymer is raised in block copolymerization.

DISCLOSURE OF THE INVENTION

The solid catalyst component (hereinafter occasionally referred to as"solid catalyst component (A)") for polymerization of olefins of thepresent invention for accomplishing the foregoing objects ischaracterized in that it is prepared from the following components (a)to (d):

(a) a dialkoxymagnesium or diaryloxymagnesium represented by the generalformula:

    Mg(OR.sup.1).sub.2

wherein R¹ represents a C₁₋₄ alkyl or aryl group;

(b) a titanium compound represented by the general formula:

    Ti(OR.sup.2).sub.p X.sub.4-p

wherein R² represents a C₁₋₄ alkyl group; X represents a halogen atom;and p represents 0 or an integer of from 1 to 3;

(c) a diester of aromatic dicarboxylic acid; and

(d) a cyclic or chain polysiloxane.

The catalyst for polymerization of olefins of the present invention isalso characterized in that it comprises the foregoing solid catalystcomponent (A), and the following components (B) and (C):

(B) an organic aluminum compound represented by the general formula:

    R.sup.3.sub.q AlQ.sub.3-q

wherein R³ represents a C₁₋₄ alkyl group; Y represents a hydrogen,chlorine, bromine or iodine atom; and q represents a real number of frommore than 0 to not more than 3; and

(C) an organic silicon compound represented by the general formula:

    R.sup.4.sub.r Si(OR.sup.5).sub.4-r

wherein R⁴ represents the same or different alkyl, cycloalkyl, phenyl,vinyl, allyl or aralkyl group; R⁵ represents the same or different C₁₋₄alkyl, cycloalkyl, phenyl, vinyl, allyl or aralkyl group; and rrepresents 0 or an integer of from 1 to 3.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a flow chart illustrating the process for the production ofthe catalyst for polymerization of olefins according to the presentinvention.

FIG. 2 is a schematic diagram illustrating an apparatus used formeasuring the flowability of the copolymer in the examples.

BEST EMBODIMENT FOR IMPLEMENTING THE INVENTION

Preferred examples of the dialkoxymagnesium or diaryloxymagnesiumrepresented by the general formula: Mg(OR¹)₂ (wherein R¹ represents aC₁₋₄ alkyl or aryl group) as component (a) (hereinafter occasionallyreferred to as "component (a)") constituting the solid catalystcomponent (A) of the present invention (hereinafter occasionallyreferred to as "component (A)") include dimethoxymagnesium,diethoxymagnesium, di-n-propoxymagnesium, di-iso-propoxymagnesium,di-n-butoxymagnesium, di-iso-butoxymagnesium, diphenoxymagnesium,ethoxymethoxymagnesium, ethoxy-n-propoxymagnesium,n-butoxyethoxymagnesium, and iso-butoxyethoxymagnesium. Thesedialkoxymagnesiums or diaryloxymagnesiums may be used singly or incombination of two or more of them. Particularly preferred among thesedialkoxymagnesiums or diaryloxymagnesiums is diethoxymagnesium ordi-n-propoxymagnesium.

Further, the dialkoxymagnesium or diaryloxymagnesium may be used ingranular or powder form to prepare the solid catalyst component (A) inthe present invention. The particle shape of the dialkoxymagnesium ordiaryloxymagnesium may be amorphous or spherical. If a sphericalparticulate dialkoxymagnesium or diaryloxymagnesium is used, a polymerpowder having a better particle shape and a narrower particle sizedistribution can be obtained. Thus, the polymer powder produced can bebetter handled during the polymerization, eliminating troubles such asblocking caused by the fine powder contained in the polymer powderproduced.

The foregoing spherical particulate dialkoxymagnesium ordiaryloxymagnesium does not necessarily need to be round but may beellipsoidal or pebble-like. In some detail, the sphericity of theparticle is not more than 3, preferably from 1 to 2, more preferablyfrom 1 to 1.5 as calculated in terms of ratio of major axis length l tominor axis length w (l/w).

Further, the foregoing dialkoxymagnesium or diaryloxymagnesium may havean average particle diameter of from 1 μm to 200 μm, preferably from 5μm to 150 μm. Further, the foregoing dialkoxymagnesium ordiaryloxymagnesium has a specific surface area of from 5 to 50 m² /g,preferably from 10 to 40 m² /g, more preferably from 15 to 30 m² /g.

The foregoing spherical particulate dialkoxymagnesium ordiaryloxymagnesium has an average particle diameter of from 1 μm to 100μm, preferably from 5 μm to 50 μm, more preferably from 10 μm to 40 μm.Further, referring to its particle size, the foregoing sphericalparticulate compound preferably has a sharp particle size distributioncomprising less fine or coarse powder. In some detail, the particle sizedistribution comprises particles having a particle size of not more than5 μm in an amount of not more than 20%, preferably not more than 10%,and particles having a particle size of at least 100 μm in an amount ofnot more than 10%, more preferably not more than 5%. The particle sizedistribution is not more than 3, preferably not more than 2, ascalculated in terms of ln (D90/D10) (wherein D90 represents the particlediameter at the point where the accumulated particle size reaches 90%and D10 represents the particle diameter at the point where theaccumulated particle size reaches 10%).

The spherical particulate dialkoxymagnesium or diaryloxymagnesium to beused normally has a bulk density of from 0.20 to 0.35 g/ml as determinedaccording to JIS K6721. In general, if a solid catalyst componentcomprising a spherical particulate dialkoxymagnesium ordiaryloxymagnesium having such a high bulk density is used to effectpolymerization of olefins, a polymer having a higher bulk density can beobtained. In the present invention, even if the spherical particulatedialkoxymagnesium or diaryloxymagnesium used has a bulk density asrelatively low as less than 0.25 g/ml, for example, the bulk density ofthe polymer produced in the presence of a solid catalyst componentcomprising such a spherical particulate dialkoxymagnesium ordiaryloxymagnesium is not lowered. Thus, a polymer having a high bulkdensity can be obtained.

The component (b) to be used in the preparation of the solid catalystcomponent (A) of the present invention is a titanium compound(hereinafter occasionally referred to as "component (b)") represented bythe general formula: Ti(OR²)_(p) X_(4-p) (wherein R² represents a C₁₋₄alkyl group; X represents a halogen atom; and p represents 0 or aninteger of from 1 to 3). Examples of such a titanium compound includetitanium halide and alkoxytitanium halide. Specific examples of thetitanium tetrahalide include TiCl₄, TiBr₄, and TiI₄. Specific examplesof the alkoxytitanium halide include Ti(OCH₃)Cl₃, Ti(OC₂ H₅)Cl₃, Ti(OC₃H₇)Cl₃, Ti(O--(n)C₄ H₉)--Cl₃, Ti(OCH₃)₂ Cl₂, Ti(OC₂ H₅)₂ Cl₂, Ti(OC₃H₇)₂ Cl₂, Ti(O--(n)C₄ H₉)₂ Cl₂, Ti(OCH₃)₃ Cl, Ti(OC₂ H₅)₃ Cl, Ti(OC₃H₇)₃ Cl, and Ti(O--(n)C₄ H₉)₃ Cl. Preferred among these titaniumcompounds is titanium tetrahalide. Particularly preferred is TiCl₄.These titanium compounds may be used singly or in combination of two ormore of them. The component (b) may be dissolved in and diluted with anorganic solvent such as aromatic hydrocarbon (e.g., toluene, xylene) andaliphatic hydrocarbon (e.g., hexane, heptane) before use.

Particularly preferred as the diester of aromatic dicarboxylic acid ascomponent (c) (hereinafter occasionally referred to as "component (c)")to be used for the preparation of the solid catalyst component (A) ofthe present invention is a C₁₋₁₂ straight-chain or branched alkyldiester of phthalic acid. Specific examples of such a diester includedimethyl phthalate, diethyl phthalate, di-n-propyl phthalate,di-iso-propyl phthalate, di-n-butyl phthalate, di-iso-butyl phthalate,ethyl methyl phthalate, butyl ethyl phthalate, methyl (iso-propyl)phthalate, ethyl (n-propyl) phthalate, ethyl (n-butyl) phthalate,di-n-pentyl phthalate, di-iso-pentyl phthalate, dihexyl phthalate,di-n-hepthyl phthalate, di-n-octyl phthalate, bis(2-methylhexyl)phthalate, bis(2-ethylhexyl) phthalate, di-n-nonyl phthalate,di-iso-decyl phthalate, bis(2,2-dimethylheptyl) phthalate, n-butyl(iso-hexyl) phthalate, ethyl (iso-octyl) phthalate, n-butyl (iso-octyl)phthalate, n-pentyl (n-hexyl) phthalate, n-pentyl (iso-hexyl) phthalate,iso-pentyl (n-heptyl) phthalate, n-pentyl (iso-octyl) phthalate,n-pentyl (iso-nonyl) phthalate, iso-pentyl (n-decyl) phthalate, n-pentyl(n-undecyl) phthalate, iso-pentyl (iso-hexyl) phthalate, n-hexyl(iso-octyl) phthalate, n-hexyl (iso-nonyl) phthalate, n-hexyl (n-decyl)phthalate, n-heptyl (iso-octyl) phthalate, n-heptyl (iso-nonyl)phthalate, n-heptyl (neo-decyl) phthalate, iso-octyl (iso-nonyl)phthalate, dicyclohexyl phthalate, and butylbenzyl phthalate. Thesephthalic acid esters may be used singly or in combination of two or moreof them. Preferred among these phthalic acid esters are diethylphthalate, di-n-butyl phthalate, di-iso-butyl phthalate, andbis(2-ethylhexyl) phthalate.

If two or more of these components (c) are used in combination, at leasttwo diesters of aromatic dicarboxylic acid selected in such a mannerthat the difference in the sum of the number of carbon atoms in twoalkyl groups in respective diesters of aromatic dicarboxylic acid is atleast 4 may be used (hereinafter the diester of aromatic dicarboxylicacid having more carbon atoms in two alkyl groups than the other will beoccasionally referred to as "component (c1)", and the other will beoccasionally referred to as "component (c2)").

Preferably, two or more diesters of phthalic acid may be used. Theircombination is preferably such that the difference between the sum ofthe number of carbon atoms contained in two alkyl groups in one diesterof phthalic acid and the sum of the number of carbon atoms contained intwo alkyl groups in another diester of phthalic acid is at least 4.Specific examples of such a combination will be given below.

    ______________________________________           Component (c1)    Component (c2)    ______________________________________    1)     Di-n-butyl phthalate                             Diethyl phthalate    2)     Di-iso-butyl phthalate                             Diethyl phthalate    3)     Bis(2-ethylhexyl) phthalate                             Diethyl phthalate    4)     Di-n-octyl phthalate                             Diethyl phthalate    5)     Di-iso-decyl phthalate                             Diethyl phthalate    6)     Butylbenzyl phthalate                             Diethyl phthalate    7)     Di-n-hexyl phthalate                             Diethyl phthalate    8)     Di-iso-hexyl phthalate                             Diethyl phthalate,    9)     Bis(2-ethylhexyl) phthalate                             Di-n-propyl phthalate    10)    Di-n-octyl phthalate                             Di-n-propyl phthalate    11)    Di-iso-decyl phthalate                             Di-n-propyl phthalate    12)    Butylbenzyl phthalate                             Di-n-propyl phthalate    13)    Di-n-hexyl phthalate                             Di-n-propyl phthalate    14)    Di-iso-hexyl phthalate                             Di-n-propyl phthalate    15)    Bis(2-ethylhexyl) phthalate                             Di-iso-butyl phthalate    16)    Di-n-octyl phthalate                             Di-iso-butyl phthalate    17)    Di-iso-decyl phthalate                             Di-iso-butyl phthalate    18)    Butylbenzyl phthalate                             Di-iso-butyl phthalate    19)    Di-n-hexyl phthalate                             Di-iso-butyl phthalate    20)    Di-iso-hexyl phthalate                             Di-iso-butyl phthalate    21)    Bis(2-ethylhexyl) phthalate                             Di-n-butyl phthalate    22)    Di-n-octyl phthalate                             Di-n-butyl phthalate    23)    Di-iso-decyl phthalate                             Di-n-butyl phthalate    24)    Butylbenzyl phthalate                             Di-n-butyl phthalate    25)    Di-n-hexyl phthalate                             Di-n-butyl phthalate    26)    Di-iso-hexyl phthalate                             Di-n-butyl phthalate    27)    Bis(2-ethylhexyl) phthalate                             Diethyl phthalate and                             di-n-butyl phthalate    28)    Bis(2-ethylhexyl) phthalate                             Diethyl phthalate and                             di-iso-butyl phthalate    ______________________________________

As mentioned above, at least two diesters of aromatic dicarboxylic acidselected in such a manner that the difference in the sum of the numberof carbon atoms in two alkyl groups in respective diesters of aromaticdicarboxylic acid is at least 4 are preferably used in combination. Inparticular, there are preferably used in combination a diester ofphthalic acid the total number of carbon atoms in two alkyl groups ofwhich is at least 10 as the component (c1) and a diester of phthalicacid the total number of carbon atoms in two alkyl groups of which isnot more than 8 as the component (c2).

In the preparation of the solid catalyst component (A), the foregoingdiester of aromatic dicarboxylic acid as an essential component may beused in combination with other electron donor compounds. As such anelectron donor compound there may be used an organic compound containingoxygen or nitrogen. Examples of such an organic compound includealcohols, phenols, ethers, esters, ketones, acid halides, aldehydes,amines, amides, nitrites, isocyanates, and organic silicon compoundcontaining Si-O-C bond. Specific examples of these organic compoundsinclude alcohols such as methanol, ethanol, propanol, butanol, pentanol,hexanol, octanol, 2-ethylhexanol and dodecanol, phenols such as phenoland cresol, ethers such as methyl ether, ethyl ether, propyl ether,butyl ether, amyl ether and diphenyl ether, monocarboxylic acid esterssuch as methyl formate, ethyl acetate, vinyl acetate, propyl acetate,octyl acetate, cyclohexyl acetate, ethyl propionate, ethyl butyrate,methyl benzoate, ethyl benzoate, propyl benzoate, butyl benzoate, octylbenzoate, cyclohexyl benzoate, phenyl benzoate, methyl p-toluylate,ethyl p-toluylate, methyl anisate and ethyl anisate, diesters ofdicarboxylic acid such as diethyl maleate, dibutyl maleate, dimethyladipate, diethyl adipate, dipropyl adipate, dibutyl adipate, dimethyladipate, diisodecyl adipate and dioctyl adipate, ketones such asacetone, methyl ethyl ketone, methyl butyl ketone, acetophenone andbenzophenone, acid halides such as phthalic acid dichloride andterephthalic acid dichloride, aldehydes such as acetaldehyde,propionaldehyde, octylaldehyde and benzaldehyde, amines such asmethylamine, ethylamine, tributylamine, piperidine, aniline andpyridine, and nitriles such as acetonitrile, benzonitrile andtrinitrile.

Specific examples of the organic silicon compound containing Si-O-C bondinclude trimethylmethoxysilane, trimethylethoxysilane,tri-n-propylmethoxysilane, tri-n-propylethoxysilane,tri-n-butylmethoxysilane, tri-isobutylmethoxysilane,tri-t-butylmethoxysilane, tri-n-butylethoxysilane,tricyclohexylmethoxysilane, tricyclohexylethoxysilane,dimethyldimethoxysilane, dimethyldiethoxysilane,di-n-propyldimethoxysilane, di-iso-propyldimethoxysilane,di-n-propyldiethoxysilane, di-iso-propyldiethoxysilane,di-n-butyldimethoxysilane, di-iso-butyldimethoxysilane,di-t-butyldimethoxysilane, di-n-butyldiethoxysilane,n-butylmethyldimethoxysilane, bis(2-ethylhexyl)dimethoxysilane,bis(2-ethylhexyl)diethoxysilane, dicyclohexyldimethoxysilane,dicyclohexyldiethoxysilane, dicyclopentyldimethoxysilane,dicyclopentyldiethoxysilane, cyclohexylmethyldimethoxysilane,cyclohexylmethyldiethoxysilane, cyclohexylethyldimethoxysilane,cyclohexyl(iso-propyl)dimethoxysilane, cyclohexylethyldiethoxysilane,cyclopentylmethyldimethoxysilane, cyclopentylethyldiethoxysilane,cyclopentyl(iso-propyl)dimethoxysilane,cyclohexyl(n-pentyl)-dimethoxysilane,cyclopentyl(iso-butyl)dimethoxysilane,cyclohexylcyclopentyldimethoxysilane,cyclohexylcyclopentyldiethoxysilane, diphenyldimethoxysilane,diphenyldiethoxysilane, phenylmethyldimethoxysilane,phenylmethyldiethoxysilane, phenylethyldimethoxysilane,phenylethyldiethoxysilane, cyclohexyldimethylmethoxysilane,cyclohexyldimethylethoxysilane, cyclohexyldiethylmethoxysilane,cyclohexyldiethylethoxysilane, 2-ethylhexyltrimethoxysilane,2-ethylhexyltriethoxysilane, cyclohexyl(n-pentyl)diethoxysilane,cyclopentylethyldimethoxysilane, cyclopentylmethyldiethoxysilane,cyclohexyl(n-propyl)dimethoxysilane, cyclohexyl(n-butyl)dimethoxysilane,cyclohexyl(n-propyl)diethoxysilane, cyclohexyl(n-butyl)diethoxysilane,methyltrimethoxysilane, methyltriethoxysilane, ethyltrimethoxysilane,ethyltriethoxysilane, n-propyltrimethoxysilane, n-propyltriethoxysilane,iso-propyltrimethoxysilane, iso-propyltriethoxysilane,n-butyltrimethoxysilane, iso-butyltrimethoxysilane,t-butyltrimethoxysilane, n-butyltriethoxysilane,cyclohexyltrimethoxysilane, cyclohexyltriethoxysilane,cyclopentyltrimethoxysilane, cyclopentyltriethoxysilane,vinyltrimethoxysilane, vinyltriethoxysilane,2-ethylhexyltrimethoxysilane, 2-ethylhexyltriethoxysilane,phenyltrimethoxysilane, phenyltriethoxysilane, tetramethoxysilane, andtetraethoxysilane.

The cyclic or chain polysiloxane (hereinafter occasionally referred toas "component (d)") to be used as component (d) in the preparation ofthe solid catalyst component (A) of the present invention will befurther described hereinafter. As such cyclic polysiloxanes there may beused one or more cyclic polysiloxanes represented by the followinggeneral formula I!: ##STR1## wherein R⁶ to R¹¹ each independentlyrepresents a hydrogen atom, methyl group or ethyl group; and nrepresents an integer of from 1 to 20.

Preferred among the cyclic polysiloxanes represented by the foregoinggeneral formula I! are those wherein n is from 1 to 10, preferably from1 to 6. Specific examples of such cyclic polysiloxanes includehexamethylcyclotrisiloxane, octamethylcyclotetrasiloxane,decamethylcyclopentasiloxane, 2,4,6-trimethylcyclotrisiloxane, and2,4,6,8-tetramethylcyclotetrasiloxane. These cyclic polysiloxanes may beused singly or in combination of two or more of them.

As chain polysiloxanes there may be used one or more compoundsrepresented by the following general formula II!: ##STR2##

In the foregoing general formula II!, x represents an averagepolymerization degree of from 2 to 30,000. Most of R¹² to R¹⁹ eachrepresents a methyl group. Some of R¹² to R¹⁹ each represents a phenylgroup, higher aliphatic acid residue, epoxy-containing group orpolyoxyalkylene-substituted group.

The polysiloxane is known generically as silicone oil. It is a chainpolysiloxane having a viscosity of from 2 to 10,000 cSt, preferably from2 to 1,000 cSt, more preferably from 3 to 500 cSt, at 25° C. whichnormally stays liquid or viscous.

Examples of the foregoing chain polysiloxane include dimethylpolysiloxane, methyl phenyl polysiloxane, higher aliphaticacid-substituted dimethylsiloxane, epoxy-substituted dimethylsiloxane,and polyoxyalkylene-substituted dimethylsiloxane.

Specific examples of these polysiloxanes include TSF400, TSF401, TSF404,TSF405, TSF4045, TSF410, TSF411, TSF433, TSF437, TSF4420, TSF451-5A,TSF451-10A, TSF451-50A, TSF451-100, TSF483, and TSF484 available fromToshiba Silicone Co., Ltd.!, and KF96, KF96L, KF96H, KF69, KF92, KF961,KF965, KF56, KF99, KF94, KF995, KF105, KF351, HIVAC-F4, and HIVAC-F5available from Shin-Etsu Chemical Co., Ltd.!.

The reaction of one or more of the foregoing cyclic or chainpolysiloxanes in combination with other components (a) to (d) makes itpossible to obtain a solid catalyst component having a high activitywhich can provide a polymer having a high stereoregularity, an extremelysmall content of fine powder and a high bulk density. These cyclic orchain polysolixanes may be dissolved in an organic solvent such astoluene, xylene, hexane and heptane before use.

The solid catalyst component (A) of the present invention may beprepared by allowing the components (a), (b), (c) and (d) to come intocontact with one another. This preparation process can proceed in theabsence of inert organic solvent but preferably in the presence of inertorganic solvent taking into account the ease of operation. Examples ofthe inert organic solvent employable herein include saturatedhydrocarbon such as hexane, heptane and cyclohexane, aromatichydrocarbon such as benzene, toluene, xylene and ethylbenzene, andhalogenated hydrocarbon such as orthodichlorobenzene, methylenechloride, carbon tetrachloride and dichloroethane. In particular,aromatic hydrocarbons having a boiling point of from 90° C. to 150° C.are preferred. Specific examples of such aromatic hydrocarbons includetoluene, xylene, and ethylbenzene. The proportion of the component (b)is from 0.1 to 200 ml, preferably from 0.5 to 100 ml per g of thecomponent (a). The proportion of the component (c) is from 0.01 to 3.0g, preferably from 0.1 to 1.5 g per g of the component (a). Theproportion of the component (d) is from 0.01 to 20 g, preferably from0.05 to 10 g per g of the component (a).

If at least two components (c) are used as mentioned above, theproportion of the component (c1) is from 0.01 to 2.0 g, preferably from0.1 to 1.0 g per g of the component (a), and the proportion of thecomponent (c2) is from 0.01 to 1.0 g, preferably from 0.1 to 0.5 g per gof the component (a).

The amount of the inert organic solvent to be used is not specificallylimited. It is preferably from 0.1 to 10 times by volume the component(b) taking into account operational conditions. These components may beadded batchwise during contact. Alternatively, one or more compounds maybe properly selected.

The contact of these components may be effected in an atmosphere ofinert gas free of water with stirring in a vessel equipped with anagitator. The contact of these components may be effected at arelatively low temperature in the vicinity of room temperature if theyare merely stirred and mixed or subjected to dispersion or suspension toundergo modification. If these components are reacted after contacted toobtain a reaction product, the contact is preferably effected within atemperature range of from 40° C. to 130° C. If the reaction temperaturefalls below 40° C., the reaction cannot proceed sufficiently, resultingin the production of a solid catalyst component having insufficientproperties. On the contrary, if the reaction temperature exceeds 130°C., the solvent used remarkably evaporates, making it difficult tocontrol the reaction. The reaction time is at least 1 minute, preferablyat least 10 minutes, more preferably at least 30 minutes.

In the preparation of the solid catalyst component (A) of the presentinvention, the components (a), (b), (c) and (d) are allowed to come incontact with one another. The order of contact of these components isarbitrary and not specifically limited. Specific examples of theprocedure of addition of these components will be given below.

1. The components (a), (b), (c) and (d) are allowed to come in contactwith one another at the same time.

2. The component (d) is allowed to come in contact with a solid reactionproduct obtained by allowing the components (a), (b) and (c) to come incontact with one another.

3. The component (d) is allowed to come in contact with a solid reactionproduct obtained by allowing the components (a), (b) and (c) to come incontact with one another. The component (b) is then repeatedly allowedto come in contact with the resulting reaction product.

4. The components (b) and (d) are allowed to come in contact with asolid reaction product obtained by allowing the components (a) and (c)to come in contact with each other.

5. The components (b) and (d) are allowed to come in contact with asolid reaction product obtained by allowing the components (a) and (c)to come in contact with each other. The component (b) is then repeatedlyallowed to come in contact with the resulting reaction product.

6. The components (c) and (d) are allowed to come in contact with asolid reaction product obtained by allowing the components (a) and (b)to come in contact with each other. The component (b) is then repeatedlyallowed to come in contact with the resulting reaction product.

7. The components (c) and (d) are allowed to come in contact with asolid reaction product obtained by allowing the components (a) and (b)to come in contact with each other.

8. The component (c) is allowed to come in contact with a solid reactionproduct obtained by allowing the components (a) and (b) to come incontact with each other. The component (b) is then repeatedly allowed tocome in contact with the resulting reaction product. The component (d)is then allowed to come in contact with the resulting reaction product.

9. The components (c) and (d) are allowed to come in contact with asolid reaction product obtained by allowing the components (a) and (b)to come in contact with each other. The components (b) and (d) are thenrepeatedly allowed to come in contact with the resulting reactionproduct.

The order of contact of the component (d) in the reaction of the variouscomponents is arbitrary. Preferably, the component (d) is allowed tocome in contact with a solid reaction product obtained by allowing thecomponents (a), (b) and (c) to come in contact with one another toenhance the bulk density of the polymer thus obtained and minimize thecontent of fine powder in the polymer thus obtained. In the foregoingreaction, the component (b) is repeatedly allowed to come in contactwith the resulting solid reaction product within a temperature range offrom 40° C. to 130° C. for 1 minute or longer, preferably 5 minutes orlonger, more preferably 10 minutes or longer. In this case, thecomponent (b) may be added as it is or may be diluted properly with theforegoing inert organic solvent before being added. The latter additionmethod is preferred. In a preferred embodiment of the present invention,the solid reaction product obtained by contact and reaction of thevarious components at the previous stage is washed with the foregoinginert organic solvent before the repeated contact with the component(b).

Alternatively, the suspension of the solid reaction product obtained byallowing the components (a), (b) and (c) to come in contact with oneanother or the solid reaction product obtained by allowing thecomponents (a) and (b) to come in contact with each other may be heatedto a temperature where it is then allowed to undergo reaction with thecomponent (c) and/or (d). The average rate of heat rise from thetemperature at which the various components are suspended first to thereaction is predetermined to a range of from 0.1 to 20° C./min., morepreferably from 0.2 to 10° C./min., particularly preferably from 0.3 to8° C./min. If the rate of heat rise is too low, the polymer produced inthe presence of the solid catalyst component thus obtained exhibits aninsufficient bulk density. On the contrary, if the rate of heat rise istoo high, the resulting reaction heat is so high as to destroy theparticles. The solid catalyst component thus prepared has an increasedcontent of fine powder. As a result, the polymer produced in thepresence of the solid catalyst component has an increased content offine powder.

Further, if two or more components (c) are used, the component (c1) isfirst allowed to come in contact with the component (a), and thecomponent (c2) is then allowed to come in contact with the component(a). Preferably, the contact of the components (a), (b) and (c1) isfollowed by the contact of the component (c2). In this process, thecomponents (c1) and (c2) may be each collectively added or may be eachbatchwise added. Further, two or more components (c1) and two or morecomponents (c2) may be used.

Examples of the procedure of contact of the various components in thecase where two or more components (c) are used will be given below.

1. The component (d) is allowed to come in contact with a solid reactionproduct obtained by allowing the components (a), (b) and (c1) to come incontact with one another, and then allowing the component (c2) to comein contact with the resulting reaction product.

2. The component (d) is allowed to come in contact with a solid reactionproduct obtained by allowing the components (a), (b) and (c1) to come incontact with one another, and then allowing the component (c2) to comein contact with the resulting reaction product. The component (b) isthen repeatedly allowed to come in contact with the resulting reactionproduct.

3. The components (b), (c2) and (d) are allowed to come in contact witha solid reaction product obtained by allowing the components (a) and(c1) to come in contact with each other.

4. The components (b), (c2) and (d) are allowed to come in contact witha solid reaction product obtained by allowing the components (a) and(c1) to come in contact with each other. The component (b) is thenrepeatedly allowed to come in contact with the resulting reactionproduct.

5. The component (c1) is allowed to come in contact with a solidreaction product obtained by allowing the components (a) and (b) to comein contact with each other. The component (c2) is then allowed to comein contact with the resulting reaction product. The component (d) isthen allowed to come in contact with the resulting reaction product. Thecomponent (b) is then repeatedly allowed to come in contact with theresulting reaction product.

6. The components (c1) and (d) are allowed to come in contact with asolid reaction product obtained by allowing the components (a) and (b)to come in contact with each other. The components (b) and (c2) are thenallowed to come in contact with the resulting reaction product.

7. The component (c1) is allowed to come in contact with a solidreaction product obtained by allowing the components (a) and (b) to comein contact with each other. The component (b) is repeatedly allowed tocome in contact with the resulting reaction product. The components (c2)and (d) are then allowed to come in contact with the resulting reactionproduct.

8. The components (c1) and (d) are allowed to come in contact with asolid reaction product obtained by allowing the components (a) and (b)to come in contact with each other. The components (b), (c2) and (d) arerepeatedly allowed to come in contact with the resulting reactionproduct.

The temperature at which the component (c) is allowed to come in contactwith the other component(s) or the reaction product is not specificallylimited but is preferably not higher than 130° C. If two or morecomponents (c) are used, the component (c1) is allowed to come incontact with the other component(s) or the reaction product at atemperature of lower than 70° C., preferably from 0° C. to 55° C., whilethe component (c2) is allowed to come in contact with the othercomponent(s) or the reaction product at a temperature of from 70° C. to130° C. However, the temperature at which the component (c2) is allowedto come in contact with the other component(s) or the reaction productis not specifically limited as far as the contact of the component (c2)is effected after the contact of the component (c1).

The foregoing process for the preparation of a solid catalyst componentwhich comprises allowing two or more diesters of aromatic dicarboxylicacid, one having a great total number of carbon atoms in two estersubstituents, in particular at least 10, and the other having a smalltotal number of carbon atoms in two ester substituents, in particularnot more than 8, i.e., components (c1) and (c2) to come in contact withthe other component(s) or the reaction product in an order as describedabove, that is, in this order makes it possible to inhibit theagglomeration of solid particles during preparation. Further, the solidcatalyst component finally obtained has a reduced content of finepowder. As a result, the use of the solid catalyst component thusprepared makes it possible to produce a polymer having a small contentof coarse powder and fine powder and a high bulk density.

Specific examples of the process for the preparation of the solidcatalyst component (A) will be given below.

Example 1: Diethoxymagnesium is suspended as the component (a) in anaromatic hydrocarbon solvent such as toluene within a temperature rangeof from -10° C. to 30° C. To the suspension thus obtained is addedtitanium tetrachloride as the component (b). In this procedure, theamount of titanium tetrachloride is preferably not more than 1/2 byvolume of the solvent in which the component (a) is suspended.Subsequently, to the suspension is added dibutyl phthalate as thecomponent (c). The temperature at which this procedure is effected isthe same as used in the suspension of the component (a) in toluene. Thesuspension is heated to a temperature of from 50° C. to 110° C. wheredecamethylcyclopentasiloxane or dimethylpolysiloxane is then addedthereto as the component (d). Thereafter, the reaction system is heatedto a temperature of from 100° C. to 120° C. where it is then kept toundergo reaction for 30 minutes to 3 hours to obtain a solid reactionproduct. The solid reaction product is then washed with toluene within atemperature range of from 40° C. to 130° C. for 1 minute or longer. Tothe resulting solid reaction product are then added toluene and titaniumtetrachloride so that they are allowed to come in contact with oneanother. The reaction system is heated to a temperature of from 100° C.to 120° C. where it is then kept to undergo reaction for 30 minutes to 3hours. The solid reaction product is washed with heptane to obtain asolid catalyst component (A).

Example 2: Diethoxymagnesium is suspended as the component (a) in anaromatic hydrocarbon solvent such as toluene within a temperature rangeof from -10° C. to 30° C. To the suspension thus obtained is addedtitanium tetrachloride as the component (b). In this procedure, theamount of titanium tetrachloride is preferably not more than 1/2 byvolume of the solvent in which the component (a) is suspended.Subsequently, to the suspension is added di-iso-octyl phthalate as thecomponent (c1) within a temperature range of from 30° C. to 60° C.Further, to the suspension is added diethyl phthalate as the component(c2) within a temperature range of from 60° C. to 80° C. Subsequently,the suspension is heated to a temperature of from 80° C. to 110° C.where decamethylcyclopentasiloxane or dimethylpolysiloxane is then addedthereto as the component (d). Thereafter, the reaction system is furtherheated to a temperature of from 100° C. to 120° C. where it is then keptto undergo reaction for 30 minutes to 3 hours to obtain a solid reactionproduct. The solid reaction product is washed with titaniumtetrachloride diluted with toluene and then with toluene within atemperature range of from 40° C. to 130° C. for 1 minute or longer. Tothe resulting solid reaction product are then added toluene and titaniumtetrachloride so that they are allowed to come in contact with oneanother. The reaction system is heated to a temperature of from 100° C.to 120° C. where it is then kept to undergo reaction for 30 minutes to 3hours. The solid reaction product is washed with heptane to obtain asolid component (A).

Example 3: Diethoxymagnesium as the component (a) and di-iso-decylphthalate as the component (c1) are allowed to come in contact with eachother in an aromatic hydrocarbon solvent such as toluene. To theresulting reaction product is then added titanium tetrachloride as thecomponent (b) within a temperature range of from -10° C. to 30° C. Inthis procedure, the amount of titanium tetrachloride is preferably notmore than 1/2 by volume of the solvent in which the component (a) issuspended. The suspension is heated to a temperature of from 60° C. to80° C. where di-iso-butyl phthalate as the component (c2) is then addedthereto. Thereafter, to the suspension is addeddecamethylcyclopentasiloxane or dimethylpolysiloxane as the component(d) within a temperature range of from 80° C. to 110° C. Thereafter, thesuspension is heated to a temperature of from 100° C. to 120° C. whereit is then kept to undergo reaction for 30 minutes to 3 hours to obtaina solid reaction product. The solid reaction product is washed withtitanium tetrachloride diluted with toluene and then with toluene withina temperature range of from 40° C. to 130° C. for 1 minute or longer. Tothe resulting solid reaction product are then added toluene, titaniumtetrachloride and diethyl phthalate so that they are allowed to come incontact with one another. The reaction system is heated to a temperatureof from 100° C. to 120° C. where it is then kept to undergo reaction for30 minutes to 3 hours. The solid reaction product is washed with heptaneto obtain a solid component (A).

The solid catalyst component (A) of the present invention thus preparedis preferably washed with an inert organic solvent such as heptane toremove unreacted substances. The solid catalyst component (A) thuswashed is then combined with the components (B) and (C) described laterafter dried or as it is to produce a catalyst for polymerization ofolefins of the present invention.

As the organic aluminum compound (B) to be used in the present inventionthere may be used one represented by the general formula: R³ _(q)AlQ_(3-q) (in which R³ represents a C₁₋₄ alkyl group; Y represents ahydrogen atom, chlorine atom, bromine atom or iodine atom; and qrepresents a real number of more than 0 to not more than 3).

Examples of the organic aluminum compound (B) include triethylaluminum,diethylaluminum chloride, tri-iso-butylaluminum, diethylaluminumbromide, and ethylaluminum hydride. These organic aluminum compounds maybe used singly or in combination of two or more of them. Preferred amongthese organic aluminum compounds are triethylaluminum, andtri-iso-butylaluminum.

As the organic silicon compound (C) to be used in the present inventionthere may be used an organic silicon compound represented by the generalformula R⁴ _(r) Si(OR⁵)_(4-r) (in which R⁴ 's may be the same ordifferent and each represents a C₁₋₁₂ alkyl, cycloalkyl, phenyl, vinyl,allyl or aralkyl group; R⁵ 's may be the same or different and eachrepresents a C₁₋₄ alkyl, cycloalkyl, phenyl, vinyl, allyl or aralkylgroup; and r represents 0 or an integer of from 1 to 3).

Examples of the organic silicon compound (C) include phenylalkoxysilane,alkylalkoxysilane, phenylalkylalkoxysilane, cycloalkylakoxysilane,cycloalkylalkylalkoxysilane, and alkoxysilane.

Specific examples of the foregoing organic silicon compound (C) includetrimethylmethoxysilane, trimethylethoxysilane,tri-n-propylmethoxysilane, tri-n-propylethoxysilane,tri-n-butylmethoxysilane, tri-iso-butylmethoxysilane,tri-t-butylmethoxysilane, tri-n-butylethoxysilane,tricyclohexylmethoxysilane, tricyclohexylethoxysilane,dimethyldimethoxysilane, dimethyldiethoxysilane,di-n-propyldimethoxysilane, di-iso-propyldimethoxysilane,di-n-propyldiethoxysilane, di-iso-propyldiethoxysilane,di-n-butyldimethoxysilane, di-iso-butyldimethoxysilane,di-t-butyldimethoxysilane, di-n-butyldiethoxysilane,n-butylmethyldimethoxysilane, bis(2-ethylhexyl)dimethoxysilane,bis(2-ethylhexyl)diethoxysilane, dicyclohexyldimethoxysilane,dicyclohexyldiethoxysilane, dicyclopentyldimethoxysilane,dicyclopentyldiethoxysilane, cyclohexyliethyldimethoxysilane,cyclohexylmethyldiethoxysilane, cyclohexylethyldimethoxysilane,cyclohexyl(iso-propyl)dimethoxysilane, cyclohexylethyldiethoxysilane,cyclopentyl:ethyldimethoxysilane, cyclopentylmethyldiethoxysilane,cyclopentylethyldiethoxysilane, cyclopentyl (iso-propyl)dimethoxysilane, cyclohexyl (n-pentyl) dimethoxysilane,cyclohexyl(n-pentyl)diethoxysilane,cyclopentyl(iso-butyl)dimethoxysilane,cyclohexyl(n-propyl)-dimnethoxysilane,cyclohexyl(n-propyl)diethoxysilane, cyclohexyl(iso-propyl)diethoxysilane, cyclohexyl(n-butyl )dimethoxysilane,cyclohexyl(n-butyl)diethoxysilane, cyclohexyl(iso-butyl)dimethoxysilane,diphenyldimethoxysilane, diphenyldiethoxysilane,phenylmethyldiiethoxysilane, phenylmethyldiethoxysilane,phenylethyldimethoxysilane, phenylethyldiethoxysilane,cyclohexyldimethylmethoxysilane, cyclohexyldimethylethoxysilane,cyclohexyldiethylmethoxysilane, cyclohexyldiethylethoxysilane,2-ethylhexyltrimethoxysilane, 2-ethylhexyltriethoxysilane,methyltrimethoxysilane, methyltriethoxysilane, ethyltrimethoxysilane,ethyltriethoxysilane, n-propyltrimethoxysilane, n-propyltriethoxysilane,iso-propyltrimethoxysilane, iso-propyltriethoxysilane,n-butyltrimethoxysilane, iso-butyltrimethoxysilane,t-butyltrimethoxysilane, n-butyltriethoxysilane,cyclohexyltrimethoxysilane, cyclohexyltriethoxysilane,cyclopentyltrimethoxysilane, cyclopentyltriethoxysilane,vinyltrimethoxysilane, vinyltriethoxysilane,2-ethylhexyltrimethoxysilane, 2-ethylhexyltriethoxysilane,phenyltrimethoxysilane, phenyltriethoxysilane, tetramethoxysilane,tetraethoxysilane, cyclohexylcyclopentyldimethoxysilane,cyclohexylcyclopentyldiethoxysilane, cyclohexylcyclopentylpropoxysilane,3-methylcyclohexylcyclopentyldimethoxysilane,4-methylcyclohexylcyclopentyldimethoxysilane,3,5-dimethylcyclohexylcyclopentyldimethoxysilane,3-methylcyclohexylcyclohexyldimethoxysilane,bis(3-methylcyclohexyl)dimethoxysilane,4-methylcyclohexylcyclohexyldimethoxysilane,bis(4-methylcyclohexyl)dimethoxysilane,3,5-dimethylcyclohexylcyclohexyldimethoxysilane, andbis(3,5-dimethylcyclohexyl)dimethoxysilane.

Preferred among these organic silicon compounds aredi-n-propyldimethoxysilane, di-iso-propyldimethoxysilane,di-n-butyldimethoxysilane, di-iso-butyldimethoxysilane,di-t-butyldimethoxysilane, di-n-butyldiethoxysilane,t-butyltrimethoxysilane, dicyclohexyldimethoxysilane,dicyclohexyldiethoxysilane, cyclohexylmethyldimethoxysilane,cyclohexylmethyldiethoxysilane, cyclohexylethyldimethoxysilane,cyclohexylethyldiethoxysilane, dicyclopentyldimethoxysilane,dicyclopentyldiethoxysilane, cyclopentylmethyldimethoxysilane,cyclopentylmethyldiethoxysilane, cyclopentylethyldiethoxysilane,cyclohexylcyclopentyldimethoxysilane,cyclohexylcyclopentyldiethoxysilane,3-methylcyclohexylcyclopentyldimethoxysilane,4-methylcyclohexylcyclopentyldimethoxysilane, and3,5-dimethylcyclohexylcyclopentyldimethoxysilane. These organic siliconcompounds (C) may be used singly or in combination of two or more ofthem.

In the polymerization process of the present invention, thepolymerization of olefins is accomplished by the polymerization orcopolymerization of olefins in the presence of a catalyst made of theforegoing solid catalyst component (A), organic aluminum compound (B)and organic silicon compound (C). The ratio of the various components tobe used is arbitrary and not specifically limited unless the effects ofthe present invention are impaired. In general, the proportion of theorganic aluminum compound (B) is from 1 to 1,000 mols, preferably from50 to 500 mols per mol of titanium atom in the solid catalyst component(A). The proportion of the organic aluminum compound (C) is from 0.0020to 2 mols, preferably from 0.01 to 0.5 mols per mol of the component(B).

The catalyst for polymerization of olefins of the present invention isformed by the foregoing solid catalyst component (A), organic aluminumcompound (B) and organic silicon compound (C). As the electron donor(external electron donor) to be used during polymerization there may beused an organic compound containing oxygen or nitrogen in combinationwith the foregoing organic silicon compound (C). Specific examples ofsuch an organic compound include alcohols, phenols, ethers, esters,ketones, acid halides, aldehydes, amines, amides, nitriles, andisocyanates.

Specific examples of these organic compounds include alcohols such asmethanol, ethanol, propanol, butanol, pentanol, hexanol, octanol,2-ethylhexanol and dodecanol, phenols such as phenol and cresol, etherssuch as methyl ether, ethyl ether, propyl ether, butyl ether, amyl etherand diphenyl ether, monocarboxylic acid esters such as methyl formate,ethyl acetate, vinyl acetate, propyl acetate, octyl acetate, cyclohexylacetate, ethyl propionate, ethyl butyrate, methyl benzoate, ethylbenzoate, propyl benzoate, butyl benzoate, octyl benzoate, cyclohexylbenzoate, phenyl benzoate, methyl p-toluylate, ethyl p-toluylate,p-methoxyethyl benzoate, p-ethoxyethyl benzoate, methyl anisate andethyl anisate, dicarboxylic acid esters such as diethyl maleate, dibutylmaleate, dimethyl adipate, diethyl adipate, dipropyl adipate, dibutyladipate, dimethyl adipate, diisodecyl adipate, dioctyl adipate, dimethylphthalate, diethyl phthalate, dipropyl phthalate, dibutyl phthalate,dipentyl phthalate, dihexyl phthalate, diheptyl phthalate, dioctylphthalate, dinonyl phthalate and didecyl phthalate, ketones such asacetone, methyl ethyl ketone, methyl butyl ketone, acetophenone andbenzophenone, acid halides such as phthalic acid dichloride andterephthalic acid dichloride, aldehydes such as acetaldehyde,propionaldehyde, octylaldehyde and benzaldehyde, amines such asmethylamine, ethylamine, tributylamine, piperidine, aniline andpyridine, and nitriles such as acetonitrile, benzonitrile andtolunitrile.

A process for the preparation of the catalyst for polymerization ofolefins from the foregoing solid catalyst component (A), and organicmetal compounds (B) and organic silicon compound (C) is shown in FIG. 1.

Examples of the olefins to be homopolymerized or copolymerized in thepresence of the catalyst of the present invention include ethylene,propylene, 1-butene, and 4-methyl-1-pentene. The catalyst of the presentinvention is particularly suitable for the polymerization of propylene.The polymerization of olefins in the presence of the catalyst made ofthe foregoing solid catalyst component (A), organic aluminum compound(B) and organic silicon compound (C) is preferably preceded byprepolymerization to further enhance the catalytic activity and thestereoregularity, particle properties of the polymer thus produced andthe like. As the monomers to be used in the prepolymerization there maybe used ethylene and propylene as well as monomers such as styrene andvinylcyclohexane. The polymerization is carried out by slurrypolymerization, liquid polymerization or gas phase polymerization.During the polymerization, hydrogen may be used as a molecular weightmodifier. The polymerization temperature is not higher than 200° C.,preferably not higher than 100° C. The polymerization pressure is nothigher than 10 MPa, preferably not higher than 5 MPa, more preferablynot higher than 2.5 MPa.

The present invention will be further described in the followingexamples as compared with the comparative examples.

EXAMPLE 1

<Preparation of Solid Catalyst Component>

Into a 500-ml round flask equipped with an agitator in which the airwithin had been thoroughly replaced by nitrogen gas were charged 10 g ofdiethoxymagnesium (bulk density: 0.23 g/ml; specific surface area: 21.5m² /g; sphericity (l/w): 1.10; average particle size: 28 μm; in(D90/D10): 1.10; content of fine powder having a particle size of notmore than 5 μm: 5%) and 90 ml of toluene to make a suspension. Thesuspension thus obtained was then cooled to a temperature of 3° C. Thesuspension was then added to a solution of 30 ml of toluene and 20 ml oftitanium tetrachloride. To the suspension was then added 3.6 ml ofdi-n-butyl phthalate while the temperature thereof was kept at 3° C. Thesuspension was heated at an average rate of 1° C./min. to a temperatureof 100° C. where 3 ml of decamethylcyclopentasiloxane was then addedthereto. The temperature of the reaction system was raised to 110° C.where the suspension was then reacted for 2 hours. After the terminationof the reaction, the supernatant solution was removed. The resultingsolid reaction product was then washed with 100 ml of toluene threetimes at a temperature of 110° C. Thereafter, to the resulting solidreaction product were added 80 ml of toluene and 20 ml of titaniumtetrachloride. The mixture was then processed with stirring at atemperature of 110° C. for 2 hours. Thereafter, the resulting solidreaction product was washed with 100 ml of n-heptane of 40° C. 8 timesto obtain a solid catalyst component. The solid catalyst component wasthen measured for Ti content. The result was 1.9% by weight.

<Preparation of Polymerization Catalyst and Polymerization>

Into a 2 l autoclave equipped with an agitator in which the air withinhad been completely replaced by nitrogen gas were charged 1.32 mmol oftriethylaluminum, 0.13 mmol of cyclohexylmethyldimethoxysilane and theforegoing solid catalyst component in an amount of 0.0033 mmol ascalculated in terms of titanium atom to form a polymerization catalyst.Into the autoclave were then charged 1.5 l of hydrogen gas and 1.4 l ofliquid propylene. The mixture was then allowed to undergo polymerizationreaction at a temperature of 70° C. for 1 hour to obtain a solidpolymer 1. The properties of the catalyst thus obtained and the polymerobtained by the polymerization in the presence of the catalyst are setforth in Table 1.

The properties of the polymer set forth in Table 1 had been determinedas follows. In some detail, after the termination of the polymerizationreaction, the polymer thus produced was measured for weight (a). Thepolymer was then extracted with boiling n-heptane for 6 hours. Theresulting undissolved polymer was then measured for weight (b). Thepolymerization activity and the yield of the entire crystalline polymerwere determined by the following equations: ##EQU1##

The melt index (MI), bulk density and index of occurrence of fine powderof the polymer thus produced are also set forth in Table 1. The index ofoccurrence of fine powder (FI) was determined as follows.

Into a 1,800 ml stainless steel autoclave equipped with an agitator inwhich the air within had been thoroughly dried with nitrogen gas andthen replaced by propylene gas was charged 700 ml of n-heptane. Into theautoclave were then charged 2.10 mmol of triethylaluminum and 0.21 mmolof cyclohexylmethyldimethoxysilane while the reaction system was kept inan atmosphere of propylene gas. The reaction system was heated to atemperature of 75° C. where the foregoing solid catalyst component wasthen charged thereinto in an amount of 0.007 mmol as calculated in termsof titanium atom. Thereafter, 150 ml of hydrogen was charged into theautoclave. The mixture was then subjected to polymerization under apropylene pressure of 0.7 MPa for 3 hours. The pressure drop caused bythe progress of the polymerization was compensated for by the continuoussupply of propylene alone to keep the system pressure constant duringthe polymerization. In accordance with the foregoing polymerizationprocess, propylene was polymerized. The polymer thus produced waswithdrawn by filtration, and then dried under reduced pressure to obtaina solid polymer 2.

The index of occurrence of fine powder (FI) was calculated by thefollowing equation: ##EQU2##

The index of occurrence of fine powder (FI) indicates the occurrence offine powder during polymerization. The smaller than 1 FI is, the more isthe occurrence of fine powder.

EXAMPLE 2

The procedure of Example 1 was followed to effect the production of asolid catalyst component and the polymerization in the presence thereofexcept that octamethylcyclotetarasiloxane was used instead ofdecamethylcyclopentasiloxane. The resulting solid catalyst component wasthen measured for Ti content. The result was 1.73% by weight. Theproperties of the catalyst thus obtained and the particle properties ofa polymer produced in the presence thereof are set forth in Table 1.

EXAMPLE 3

The procedure of Example 1 was followed to effect the production of asolid catalyst component and the polymerization in the presence thereofexcept that dimethylpolysiloxane (viscosity: 100 cSt, TSF-451 availablefrom Toshiba Silicone Co., Ltd.) was used instead ofdecamethylcyclopentasiloxane. The resulting solid catalyst component wasthen measured for Ti content. The result was 1.56% by weight. Theproperties of the catalyst thus obtained and the particle properties ofa polymer produced in the presence thereof are set forth in Table 1.

EXAMPLE 4

The procedure of Example 1 was followed to effect the production of asolid catalyst component and the polymerization in the presence thereofexcept that dimethylpolysiloxane (viscosity: 10 cSt) was used instead ofdecamethylcyclopentasiloxane. The resulting solid catalyst component wasthen measured for Ti content. The result was 1.73% by weight. Theproperties of the catalyst thus obtained and the particle properties ofa polymer produced in the presence thereof are set forth in Table 1.

COMPARATIVE EXAMPLE 1

The procedure of Example 1 was followed to effect the production of asolid catalyst component and the polymerization in the presence thereofexcept that decamethylcyclopentasiloxane was not used. The resultingsolid catalyst component was then measured for Ti content. The resultwas 2.06% by weight. The properties of the catalyst thus obtained andthe particle properties of a polymer produced in the presence thereofare set forth in Table 1.

                  TABLE 1    ______________________________________                                    Compar-                                    ative                Example             Example                1       2       3     4     1    ______________________________________    Properties evaluated    Weight (a) of polymer                463     480     556   553   342    produced (g)    Weight (b) of polymer                460     478     552   549   339    insoluble in boiling    n-heptane (g)    Polymerization activity                52,800  52,600  54,900                                      60,500                                            44,600    (Y) (g/g-cat.)    Yield (t-II) of                99.3    99.4    99.2  99.4  99.2    entire crystalline    polymer (wt %)    Melt index (MI)                4.3     3.5     3.3   4.7   4.2    (g/10 min.)    Bulk density                0.45    0.44    0.45  0.44  0.41    (BD) (g/ml)    Index of occurrence of                1.14    1.20    1.00  0.95  0.78    fine powder (FI)    Melting point (° C.) 164.9 164.3 162.9    ______________________________________

EXAMPLE 5

<Preparation of Solid Catalyst Component>

A solid catalyst component was prepared in the same manner as in Example1.

<Preparation of Polymerization Catalyst and Block Copolymerization ofPropylene and Ethylene>

Into a 2 l autoclave equipped with an agitator in which the air withinhad been completely replaced by nitrogen gas were charged 1.51 mmol oftriethylaluminum, 0.151 mmol of cyclohexylmethyldimethoxysilane and theforegoing solid catalyst component in an amount of 0.0030 mmol ascalculated in terms of titanium atom to form a polymerization catalyst.Into the autoclave were then charged 6.5 l of hydrogen gas and 700 ml ofliquid propylene. The mixture was then allowed to undergoprepolymerization reaction at a temperature of 20° C. for 5 minutes. Thereaction system was heated to a temperature of 70° C. where it was thenallowed to undergo polymerization reaction for 20 minutes (1st stagepolymerization). After the termination of the 1st stage polymerization,unreacted propylene was purged from the autoclave. The air within theautoclave was then replaced by nitrogen gas. The reaction system washeated to a temperature of 65° C. where it was then subjected topolymerization for 1 hour while a 1:1 mixture of propylene and ethylenewas being supplied thereinto (2nd stage polymerization). The propertiesof the catalyst and the polymer thus obtained are set forth in Table 2.The polymerization activity was determined in accordance with the samemethod as in Example 1. The ethylene content of the copolymer obtainedwas determined by ¹³ C-NMR. The content of ethylene propylene rubber(EPR) in the copolymer obtained was determined by the following method.

Into a 1 l flask equipped with an agitator and a condenser were addedabout 2.5 g of the copolymer, 8 mg of 2,6-di-t-butyl-p-cresol and 25 mlof p-xylene. The mixture was then stirred with boiling until thecopolymer was completely dissolved. Subsequently, the flask was cooledto room temperature where it was then allowed to stand for 15 hours tocause a solid matter to be precipitated. The solid matter was thensubjected to centrifugal separation by a centrifugal separator so thatit was divided into a solid matter and a liquid phase. The solid matterthus separated was then withdrawn in a beaker. To the solid matter wasthen added 500 ml of acetone. The solid matter was stirred at roomtemperature for 15 hours, withdrawn by filtration, dried, and thenmeasured for weight (this weight will be hereinafter referred to as"A"). The liquid phase portion thus separated was similarly processed tocause the precipitation of a solid matter which was then measured forweight (this weight will be hereinafter referred to as "B"). The contentof ethylene propylene rubber (EPR) in the copolymer was calculated bythe following equation:

    EPR(wt %)={B(g)/(A(g)+B(g))}×100

The flowability of the copolymer thus obtained was evaluated by thefollowing method.

An apparatus shown in FIG. 2 was used. 50 g of the polymer obtainedabove was charged into a funnel 1. Subsequently, a dumper 2 was removedso that the polymer dropped onto a receiver 3. The time required untilthe entire polymer dropped was measured. This operation was effected forthe copolymer as well as for a propylene homopolymer (polymer obtainedin Example 2) produced using the same solid catalyst component as usedin the production of the copolymer. Assuming that the dropping time ofthe copolymer and the propylene homopolymer are T1 and T2, respectively,the flowability of the copolymer was represented by the followingequation:

    Flowability=T1/T2

EXAMPLE 6

The procedure of Example 5 was followed to effect the blockcopolymerization of propylene and ethylene except that the solidcatalyst component prepared in Example 3 was used. The properties of thecatalyst and the polymer thus obtained are set forth in Table 2.

COMPARATIVE EXAMPLE 2

The experiment procedure of Example 5 was followed except that the solidcatalyst component prepared in Comparative Example 1 was used. Theresults are set forth in Table 2. The propylene homopolymer used forevaluation of flowability was obtained in Comparative Example 1.

                  TABLE 2    ______________________________________                                       Compar-                                       ative                   Example 5  Example 6                                       Example 2    ______________________________________    Weight (a) of polymer                   305        380      229    produced (g)    Polymerization activity                   38,200     41,300   32,900    (g/g-cat.)    MI (g/10 min.) 0.83       0.85     0.83    Bulk density (g/ml)                   0.43       0.43     0.39    Ethylene content (wt %)                   19.5       18.6     16.9    EPR content (wt %)                   29.8       28.7     26.5    Flowability (T1/T2)                   0.90       0.92     0.68    ______________________________________

EXAMPLE 7

<Preparation of Solid Catalyst Component>

Into a 500-ml round flask equipped with an agitator in which the airwithin had been thoroughly replaced by nitrogen gas were charged 10 g ofdiethoxymagnesium and 80 ml of toluene to make a suspension. To thesuspension was then added 20 ml of titanium tetrachloride of roomtemperature. The suspension was heated with stirring to a temperature of50° C. where 5.2 ml of di-iso-octyl phthalate was then added thereto.The suspension was heated to a temperature of 70° C. where 1.0 ml ofdiethyl phthalate was then added thereto. To the suspension was thenadded 4.0 ml of dimethylpolysiloxane (viscosity: 100 cSt, TSF-451available from Toshiba Silicone Co., Ltd). The reaction system washeated to a temperature of 112° C. where it was then reacted for 2hours. After the termination of the reaction, the supernatant solutionwas removed. The resulting solid reaction product was processed with 80ml of toluene and 20 ml of titanium tetrachloride at a temperature of100° C. for 15 minutes, and then washed with 100 ml of toluene at atemperature of 100° C. three times. To the resulting solid reactionproduct were then added 80 ml of toluene and 20 ml of titaniumtetrachloride. The mixture was processed with stirring at a temperatureof 100° C. for 2 hours, and then washed with 100 ml of n-heptane of 40°C. 8 times to obtain a solid catalyst component. The solid catalystcomponent thus obtained was then measured for Ti content. The result was2.2% by weight.

Preparation of Polymerization Catalyst and Polymerization

Into a 2 l autoclave equipped with an agitator in which the air withinhad been thoroughly dried with nitrogen gas and then replaced bypropylene gas was charged 20 ml of n-heptane. Into the autoclave werethen charged 1.31 mmol of triethylaluminum, 0.13 mmol ofcyclohexylmethyldimethoxysilane and the foregoing solid catalystcomponent in an amount of 0.0026 mmol as calculated in terms of titaniumatom while the reaction system was kept in an atmosphere of propylene toprepare a polymerization catalyst. Into the autoclave were then charged3,000 ml of hydrogen gas and 1.4 l of liquid propylene. The mixture wasthen allowed to undergo prepolymerization reaction at a temperature of20° C. with stirring for 5 minutes. The reaction system was immediatelyheated to a temperature of 70° C. where it was then allowed to undergopolymerization reaction for 1 hour to obtain a solid polymer. Theproperties of the catalyst and the polymer thus obtained are set forthin Table 3.

EXAMPLE 8

<Preparation of Solid Catalyst Component>

Into a 500-ml round flask equipped with an agitator in which the airwithin had been thoroughly replaced by nitrogen gas were charged 10 g ofdiethoxymagnesium, 80 ml of toluene and 2.5 ml of di-iso-decyl phthalateto make a suspension. To the suspension was then added 20 ml of titaniumtetrachloride of room temperature. The suspension was heated withstirring to a temperature of 80° C. where 1.2 ml of di-iso-butylphthalate was then added thereto. To the suspension was then added 4.0ml of a dimethylpolysiloxane (viscosity: 100 cSt, TSF-451 available fromToshiba Silicone Co., Ltd.). The reaction system was heated to atemperature of 112° C. where it was then reacted for 2 hours. After thetermination of the reaction, the supernatant solution was removed. Theresulting solid reaction product was then processed with 80 ml oftoluene, 20 ml of titanium tetrachloride and 0.25 ml of diethylphthalate at a temperature of 110° C. for 30 minutes. The resultingsupernatant solution was then removed. The resulting solid reactionproduct was then washed with 100 ml of toluene at a temperature of 100°C. three times. To the resulting solid reaction product were then added80 ml of toluene and 20 ml of titanium tetrachloride. The mixture wasprocessed with stirring at a temperature of 100° C. for 2 hours, andthen washed with 100 ml of n-heptane of 40° C. 8 times to obtain a solidcatalyst component. The solid catalyst component thus obtained was thenmeasured for Ti content. The result was 2.1% by weight.

<Preparation of Polymerization Catalyst and Polymerization>

The polymerization procedure of Example 7 was followed except that thesolid catalyst component thus obtained was used. The properties of thecatalyst and the polymer thus obtained are set forth in Table 3.

EXAMPLE 9

<Preparation of Solid Catalyst Component>

Into a 500-ml round flask equipped with an agitator in which the airwithin had been thoroughly replaced by nitrogen gas were charged 10 g ofdiethoxymagnesium, 80 ml of toluene and 1.0 ml of di-iso-octyl phthalateto make a suspension. To the suspension was then added 20 ml of titaniumtetrachloride of room temperature. The suspension was heated withstirring to a temperature of 50° C. where 4.2 ml of di-iso-octylphthalate was then added thereto. To the suspension was then added 1.0ml of a diethyl phthalate at a temperature of 70° C. To the suspensionwas then added 3.0 ml of a dimethylpolysiloxane (TSF-451 available fromToshiba Silicone Co., Ltd.) at a temperature of 100° C. The reactionsystem was heated to a temperature of 112° C. where it was then reactedfor 2 hours. After the termination of the reaction, the supernatantsolution was removed. The resulting solid reaction product was thenprocessed with 80 ml of toluene and 20 ml of titanium tetrachloride at atemperature of 110° C. for 30 minutes. The resulting supernatantsolution was then removed. The resulting solid reaction product was thenwashed with 100 ml of toluene at a temperature of 100° C. three times.To the resulting solid reaction product were then added 80 ml oftoluene, 20 ml of titanium tetrachloride and 0.25 ml of diethylphthalate. The mixture was processed with stirring at a temperature of100° C. for 2 hours, and then washed with 100 ml of n-heptane of 40° C.8 times to obtain a solid catalyst component. The solid catalystcomponent thus obtained was then measured for Ti content. The result was2.3% by weight.

<Preparation of Polymerization Catalyst and Polymerization>

The polymerization procedure of Example 7 was followed except that thesolid catalyst component thus obtained was used. The properties of thecatalyst and the polymer thus obtained are set forth in Table 3.

EXAMPLE 10

<Preparation of Solid Catalyst Component>

Into a 500-ml round flask equipped with an agitator in which the airwithin had been thoroughly replaced by nitrogen gas were charged 10 g ofdiethoxymagnesium and 80 ml of toluene to make a suspension. To thesuspension was then added 20 ml of titanium tetrachloride of roomtemperature. The suspension was heated with stirring to a temperature of50° C. where 3.0 ml of butylbenzyl phthalate was then added thereto. Thesuspension was heated to a temperature of 70° C. where 1.0 ml of diethylphthalate was then added thereto. To the suspension was then added 4.0ml of a dimethylpolysiloxane (viscosity: 100 cSt, TSF-451 available fromToshiba Silicone Co., Ltd.). The reaction system was heated to atemperature of 112° C. where it was then reacted for 2 hours. After thetermination of the reaction, the supernatant solution was removed. Theresulting solid reaction product was processed with 80 ml of toluene and20 ml of titanium tetrachloride at a temperature of 100° C. for 15minutes, and then washed with 100 ml of toluene at a temperature of 100°C. three times. To the resulting solid reaction product were then added80 ml of toluene and 20 ml of titanium tetrachloride. The mixture wasprocessed with stirring at a temperature of 100° C. for 2 hours, andthen washed with 100 ml of n-heptane of 40° C. 8 times to obtain a solidcatalyst component. The solid catalyst component thus obtained was thenmeasured for Ti content. The result was 2.0% by weight.

<Preparation of Polymerization Catalyst and Polymerization>

The polymerization procedure of Example 7 was followed except that thesolid catalyst component thus obtained was used. The properties of thecatalyst and the polymer thus obtained are set forth in Table 3.

EXAMPLE 11

<Preparation of Solid Catalyst Component>

Into a 500-ml round flask equipped with an agitator in which the airwithin had been thoroughly replaced by nitrogen gas were charged 10 g ofdiethoxymagnesium and 80 ml of toluene to make a suspension. To thesuspension was then added 20 ml of titanium tetrachloride of roomtemperature. The suspension was heated with stirring to a temperature of50° C. where 5.2 ml of di-iso-octyl phthalate was then added thereto.The suspension was heated to a temperature of 70° C. where 1.0 ml ofdi-n-propyl phthalate was then added thereto. To the suspension was thenadded 4.0 ml of a dimethylpolysiloxane (viscosity: 100 cSt, TSF-451available from Toshiba Silicone Co., Ltd.). The reaction system washeated to a temperature of 112° C. where it was then reacted for 2hours. After the termination of the reaction, the supernatant solutionwas removed. The resulting solid reaction product was processed with 80ml of toluene and 20 ml of titanium tetrachloride at a temperature of100° C. for 15 minutes, and then washed with 100 ml of toluene at atemperature of 100° C. twice. The resulting solid reaction product wasthen processed with 80 ml of toluene and 0.3 ml of di-n-propyl phthalatewith stirring at a temperature of 105° C. for 30 minutes. Thereafter, tothe resulting solid reaction product were added 80 ml of toluene, 20 mlof titanium tetrachloride and 4.0 ml of a dimethylpolysiloxane (TSF-451available from Toshiba Silicone Co., Ltd.). The mixture was processedwith stirring at a temperature of 100° C. for 2 hours, and then washedwith 100 ml of n-heptane of 40° C. 8 times to obtain a solid catalystcomponent. The solid catalyst component thus obtained was then measuredfor Ti content. The result was 1.8% by weight.

<Preparation of Polymerization Catalyst and Polymerization>

The polymerization procedure of Example 7 was followed except that thesolid catalyst component thus obtained was used. The properties of thecatalyst and the polymer thus obtained are set forth in Table 3.

COMPARATIVE EXAMPLE 3

<Preparation of Solid Catalyst Component>

Into a 500-ml round flask equipped with an agitator in which the airwithin had been thoroughly replaced by nitrogen gas were charged 10 g ofdiethoxymagnesium and 80 ml of toluene to make a suspension. To thesuspension was then added 20 ml of titanium tetrachloride of roomtemperature. The suspension was heated with stirring to a temperature of90° C. where 3.5 ml of di-n-butyl phthalate was then added thereto. Thereaction system was heated to a temperature of 112° C. where it was thenreacted for 2 hours. After the termination of the reaction, thesupernatant solution was removed. The resulting solid reaction productwas then processed with 80 ml of toluene and 20 ml of titaniumtetrachloride at a temperature of 100° C. for 15 minutes. The resultingsolid reaction product was then washed with 100 ml of toluene at atemperature of 100° C. three times. To the resulting solid reactionproduct were then added 80 ml of toluene and 20 ml of titaniumtetrachloride. The mixture was processed with stirring at a temperatureof 100° C. for 2 hours, and then washed with 100 ml of n-heptane of 40°C. 8 times to obtain a solid catalyst component. The solid catalystcomponent thus obtained was then measured for Ti content. The result was3.5% by weight.

Preparation of Polymerization Catalyst and Polymerization

The polymerization procedure of Example 7 was followed except that thesolid catalyst component thus obtained was used. The properties of thecatalyst and the polymer thus obtained are set forth in Table 3.

                  TABLE 3    ______________________________________                                     Com-                                     par-                                     ative                                     Ex-             Example                 ample             7       8       9     10    11    3    ______________________________________    Properties evaluated    Polymerization             47,600  59,500  48,200                                   47,600                                         52,100                                               40,900    activity (Y)    (g/g-cat.)    Yield (t-II) of             99.0    98.9    98.9  98.8  99.1  98.0    entire    crystalline    polymer (wt %)    Melt index             7.9     8.5     9.3   11.0  10.0  11.0    (MI)    (g/10 min.)    Xylene-soluble             0.7     0.8     0.7   0.8   0.6   1.6    content (XS)    (wt %)    Bulk density             0.44    0.43    0.44  0.44  0.45  0.40    (BD) (g/ml)    Average  550     400     450   600   550   550    particle    size of polymer    (micron)    Polymer having             0.3     0.5     0.6   0.4   0.2   3.5    a particle    diameter    of 105μ or    smaller (wt %)    ______________________________________

Industrial Applicability

The catalyst according to the present invention can exhibit asufficiently high catalytic activity when used in the polymerization ofolefins, in particular propylene. As a result, the content of catalystresidue in the polymer thus produced can be minimized, making itpossible to reduce the content of chlorine remaining in the polymer thusproduced to such an extent that no deashing process is required.Further, a stereoregular polypropylene-can be produced in an extremelyhigh yield. The polypropylene thus produced has a high bulk density.Thus, an excellent polymer can be efficiently produced. Moreover, ifpolymerization is effected in the presence of the catalyst according tothe present invention, the content of fine powder in the polymer thusproduced can be reduced, making it possible to prevent any processtroubles due to fine polymer powder.

Further, the catalyst of the present invention provides the copolymerthus produced with excellent particle properties, in particularexcellent flowability, even if the production ratio of rubber-likecopolymer in block copolymerization is raised. Thus, troubles inoperation such as adhesion of particles can be eliminated.

We claim:
 1. A catalyst component for polymerization of olefins,prepared by the reaction of components consisting of the followingcomponents (a) to (d):(a) a dialkoxymagnesium or diaryloxy magnesiumrepresented by the general formula:

    Mg(OR.sup.1).sub.2

wherein R¹ represents a C₁₋₄ -alkyl or an aryl group; (b) a titaniumcompound represented by the general formula:

    Ti(OR.sup.2).sub.p X.sub.4-p

wherein R² represents a C₁₋₄ -alkyl group; X represents a halogen atom;and p represents 0 or an integer of from 1 to 3; (c) at least one C₁₋₁₂straight-chain or branched alkyl or benzyl diester of phthalic acid; and(d) a cyclic or chain polysiloxane.
 2. The catalyst component forpolymerization of olefins as claimed in claim 1, wherein said diester ofphthalic acid to be used as the component (c) comprises of at least twodiesters of phthalic acid selected in such a manner that the differencein the sum of the number of carbon atoms of the two alkyl or benzylgroups between each of the respective diesters is at least
 4. 3. Acatalyst for polymerization of olefins, prepared from the followingcomponents (A), (B) and (C):(A) a catalyst component as claimed in claim1 or 2; (B) an organic aluminum compound represented by the generalformula:

    R.sup.3.sub.q AlQ.sub.3-q

wherein R³ represents a C₁₋₄ -alkyl group; Q represents a hydrogen,chlorine, bromine or iodine atom; and q represents a real number of frommore than 0 to not more than 3; and (C) an organic silicon compoundrepresented by the general formula:

    R.sup.4.sub.r Si(OR.sup.5).sub.4-r

wherein R⁴ represents the same or different alkyl, cycloalkyl, phenyl,vinyl, allyl or aralkyl group; R⁵ represents the same or different C₁₋₄-alkyl, cycloalkyl, phenyl, vinyl, allyl or aralkyl group; and rrepresents 0 or an integer of from 1 to
 3. 4. The catalyst component forpolymerization of olefins as claimed in claim 2, wherein the at leasttwo diesters of phthalic acid are selected from the group consisting ofthe following combinations:

    ______________________________________    Component (c1) Component (c2)    ______________________________________     1) Di-n-butyl phthalate                   Diethyl phthalate     2) Di-iso-butyl phthalate                   Diethyl phthalate     3) Bis(2-ethylhexyl)phthalate                   Diethyl phthalate     4) Di-n-octyl phthalate                   Diethyl phthalate     5) Di-iso-decyl phthalate                   Diethyl phthalate     6) Butylbenzyl phthalate                   Diethyl phthalate     7) Di-n-hexyl phthalate                   Diethyl phthalate     8) Di-iso-hexyl phthalate                   Diethyl phthalate     9) Bis(2-ethylhexyl)phthalate                   Di-n-propyl phthalate    10) Di-n-octyl phthalate                   Di-n-propyl phthalate    11) Di-iso-decyl-phthalate                   Di-n-propyl phthalate    12) Butylbenzyl phthalate                   Di-n-propyl phthalate    13) Di-n-hexyl phthalate                   Di-n-propyl phthalate    14) Di-iso-hexyl phthalate                   Di-n-propyl phthalate    15) Bis(2-ethylhexyl)phthalate                   Di-iso-butyl phthalate    16) Di-n-octyl phthalate                   Di-iso-butyl phthalate    17) Di-iso-decyl phthalate                   Di-iso-butyl phthalate    18) Di-n-hexyl phthalate                   Di-iso-butyl phthalate    19) Di-iso-hexyl phthalate                   Di-iso-butyl phthalate    20) Bis(2-ethylhexyl)phthalate                   Di-n-butyl phthalate    21) Di-n-octyl phthalate                   Di-n-butyl phthalate    22) Di-iso-decyl phthalate                   Di-n-butyl phthalate    23) Di-n-hexyl phthalate                   Di-n-butyl phthalate    24) Di-iso-hexyl phthalate                   Di-n-butyl phthalate    25) Bis(2-ethylhexyl)phthalate                   Diethyl phthalate and di-n-butyl phthalate    26) Bis(2-ethylhexyl)phthalate                   Diethyl phthalate and di-iso-butyl                   phthalate.    ______________________________________